Guide to repairing tile floor, step by step

February 05, 2010|By Mike McClintock, Special to the Tribune

Perfectly prepared homeowners save a sample of every material used on the house: paint, wallpaper, trim, shingles, you name it. And when someone drops a bowling ball on the tile floor it's no problem: you've got extras.

If not, and the tile is a standard size and color, the manufacturer may still sell it. Or you could use a similar tile and try not to notice that it's a little darker or lighter. If all else fails, you might replace the broken tile with a contrasting color, and replace others to form a purposeful and symmetrical pattern.

Whatever plan works, in the end you have to remove the broken pieces, clean out the space, and set a new tile. Here's how to do it.

Removing. If tiles around the break are solid, work gingerly. Pounding with a mallet and cold chisel is likely to cause more damage. Use hand tools with a minimum amount of force, digging and prying as much as possible instead of hammering. Protect adjacent tiles if you pry, for instance, by laying a board over several tiles to spread the load.

Grout lines are often the weak link where you can work in a screwdriver and break out chunks to expose an edge of the damaged tile. Pieces of tile may pop loose, too. But tile is set in a bed of adhesive, and part or all of the tile may still be fixed to the subfloor.

Another approach is to drill several small holes in a line across the tile (with a masonry bit). This creates a fault line, and makes it easier to break the tile into smaller pieces that are easier to remove.

Clearing. Under tile on floors, you're likely to find plywood that can be scraped clean with a chisel. The old ribs of adhesive have to be cleared or the replacement tile won't set flush with the floor, or adhere well. Also clear any remaining grout around the edges. If the original tile setter did a thorough job, pieces may break free with adhesive attached. Or you may get tile plus adhesive and splinters of the subfloor. A few slivers won't hurt because you can fill the voids with fresh adhesive when you set a replacement tile. But if you dig too deeply and raise longer strips of subflooring they could pop surrounding tiles.

Under tile on walls, you'll likely find drywall. It's paper surface (and often some of the gypsum core) almost always comes away with the adhesive and requires patching. First, cut away any loose material with a utility knife. Then fill deep scars with spackle or drywall compound.

Under tile on counters (and often in bathrooms and showers), you're likely find cement board. It's reinforced masonry surface should withstand scraping without needing any filling or repairs.

In all cases, you don't have to shave away every trace of adhesive. But most tiles have ribs on the back designed to be pressed into a similarly ribbed layer of adhesive that's spread on a sound supporting surface. If you don't repair voids, and rely, for example, on a thick layer of compound to fill drywall damage, the replacement tile may sink below the wall surface.

Resetting. It's difficult to use a notched trowel (if you have one) in a small repair space. And on repair jobs you may not have the original installation information that specifies the right adhesive rib depth. For most tiles, a 3/8-inch rib will be close enough. If you can't create it with a trowel, apply about 3/8-inch of adhesive and scrape out channels to create ribs. For help controlling depth, add strips of masking tape that run across the replacement and hold it level with surrounding tiles.

After nestling the new tile in place, center it in the area to create even grout seams. Some tiles come with small nubs on the sides that automatically create the right spacing. If you have trouble judging the distance, use plastic, X-shaped spacers (available at tile suppliers and home centers), or small pieces of wood. You'll see some adhesive in the seams, but don't let it bulge up. If it fill the seams you won't have the depth needed to install the proper amount of grout.

Once the adhesive sets (usually overnight), you can add grout to finish the repair. Press it firmly into place, sweeping a float or squeegee back and forth across the seams. When it dries, wipe away the grout haze and you're done.